This invention relates generally to a coupling assembly for articulated machines and more particularly to such a coupling assembly which is bolted together.
It is well known in the prior art to provide coupling means, or a hitch, between two sections of a machine to permit articulated movement about a generally vertical pivot axis. However, such prior art hitches are typically of integral construction and are, thus, formed from only one material which may not best meet the material requirements of all portions of the hitches. For example, the portion of an articulating hitch which houses drive shaft bearings may experience significantly more wear that the portion which houses articulation bearings. In U.S. Pat. No. 3,773,129 issued to Anderson on Nov. 20, 1973, a compact unitary coupling is described for facilitating interconnection with two machine sections. There, the unitary nature of the coupling necessitates a single material of construction, which material may not best meet the requirements of hardness, durability or strength of a particular hitch portion.
Where different materials of construction are used in different hitch portions, the portions may not be separated for repair or replacement of an individual portion. For example, in the Caterpillar D300E Articulated Truck the hitch is formed of two portions, each of a different material, which are robotically welded together. While providing outstanding strength, an individual portion of a unitary welded hitch is not repairable or replaceable.
The present invention is directed to overcoming one or more of the problems set forth above.
In one aspect of the present invention, a hitch assembly for an articulated machine having front and rear sections permits articulation of the machine sections about a vertical axis. The hitch assembly includes a tube member having opposing ends, inner and outer surfaces which are wear-resistant and hardened, a plurality of fastener holes at one of the ends, a yoke member having opposing ends with one of the ends having a plurality of fastener-receiving holes which are axially alignable with the fastener holes of the tube member, and a plurality of fasteners receivable in the axially alignable holes for fastening the tube and yoke members together. The yoke member also has a pair of spaced apart receptacles for receiving pivoting means for pivoting the hitch assembly about the vertical axis, and a boss for receiving pivot actuating means. The yoke member is removably fastenable to the tube member.
In another aspect of the present invention, a hitch assembly for an articulated machine having front and rear sections permits articulation of the machine sections about a vertical axis. The hitch includes a tube member having opposing ends and inner and outer surfaces and a yoke member having opposing ends, the yoke member being removably fastenable to the tube member, and having a pair of spaced apart receptacles for receiving pivoting means for pivoting the hitch assembly about the vertical axis.